This invention relates to a self-engaging composite separable fastener product of the hook and loop-type. The invention also relates to a method of producing the inventive product.
2. Description of the Prior Art
Hook and loop fastener strips are well known and are used to join two parts detachably to each other. These fastener strips consist of mating fastener tapes having hooks and loops set respectively on either tape, which on being pressed together will interlock and so form a connection. Such fastener strips are employed in numerous applications including wearing apparel, for example outer apparel, and are also found on footwear and leather goods such as bags or the like.
Such hook and loop-type fasteners are described in U.S. Pat. Nos. 2,717,437 and 3,009,235 which are marketed under the registered trademark VELCRO brand hook and loop fasteners by Velcro USA Inc., Manchester, N.H. 03108 have gained wide acceptance because of the properties of the mating hooks and loops which permit their attachment by merely placing a surface defined by the hooks into face-to-face relationship with a surface defined by the loops so that a large number of hooks engage a large number of loops which resist separation parallel to the interfacial plane of engagement but are readily separable by peeling forces applied substantially normal to this interfacial plane. The loop component of these fasteners is generally formed of a sheet of woven fabric having raised threads of multifilament synthetic material, such as nylon, which are napped or unnapped, to provide a pile surface defined by a plurality of loops, and which may be thermally treated to become semi-rigid. The hook part of these fasteners is generally formed of a separate sheet of woven fabric having raised monofilament loops which are subsequently cut to form hooks.
While these fasteners provide excellent holding properties where repeated engagements and disengagements are required, often it is desirable to provide a continuous fastener member having one section containing upstanding loops and a second section containing upstanding hooks so as to enable portions of the fastener to be folded upon themselves to provide the necessary fastening, as by placing the fastener in tension when utilized as a fastener for footwear.
In commonly assigned U.S. Pat. No. 4,426,363 to Girard, a composite length of pile fabric sheet material is disclosed whereby two sections of such mating fastener materials are joined together. Thus the hook section can be matched with the loop section (i.e. hook and loop relative densities and heights) to provide effective fastening and separation of the sections. While this invention has been successful over the years, the fastener nevertheless requires a separate step to join the separate sections, thus not only adding to the cost of manufacture, but introducing an element of potential weakness in the strap. Moreover, since the sections are often joined by ultrasonic welding or stitching techniques the fastener sections are overlapped with each other thus creating an area of increased thickness and resistance to folding. This sometimes presents a particular disadvantage such as in footwear applications where added thickness to the fastener can cause added discomfort to the wearer.
Subsequent to the development of the fastener of U.S. Pat. No. 3,426,363 to Girard attempts were made to weave a composite fastener on a single loom whereby adjacent hook and loop tape sections could be produced having a common base member. However, these fasteners had insufficient desirable holding power because the loop density of the loop section thus produced did not match the hook density of the hook section. We have invented a composite self-engaging fastener which avoids these aforementioned disadvantages.